drm: Check user mode against overflows
The internal mode representation drm_display_mode uses signed data
types. When converting the user mode to internal representation,
check that the unsigned values don't overflow the signed datatypes.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 9ccb92f..4d9e69c 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1040,10 +1040,16 @@
*
* Convert a drm_mode_modeinfo into a drm_display_mode structure to return to
* the caller.
+ *
+ * RETURNS:
+ * Zero on success, errno on failure.
*/
-void drm_crtc_convert_umode(struct drm_display_mode *out,
- struct drm_mode_modeinfo *in)
+int drm_crtc_convert_umode(struct drm_display_mode *out,
+ struct drm_mode_modeinfo *in)
{
+ if (in->clock > INT_MAX || in->vrefresh > INT_MAX)
+ return -ERANGE;
+
out->clock = in->clock;
out->hdisplay = in->hdisplay;
out->hsync_start = in->hsync_start;
@@ -1060,6 +1066,8 @@
out->type = in->type;
strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
+
+ return 0;
}
/**
@@ -1820,7 +1828,12 @@
goto out;
}
- drm_crtc_convert_umode(mode, &crtc_req->mode);
+ ret = drm_crtc_convert_umode(mode, &crtc_req->mode);
+ if (ret) {
+ DRM_DEBUG_KMS("Invalid mode\n");
+ goto out;
+ }
+
drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
}
@@ -2492,7 +2505,12 @@
goto out;
}
- drm_crtc_convert_umode(mode, umode);
+ ret = drm_crtc_convert_umode(mode, umode);
+ if (ret) {
+ DRM_DEBUG_KMS("Invalid mode\n");
+ drm_mode_destroy(dev, mode);
+ goto out;
+ }
drm_mode_attachmode(dev, connector, mode);
out:
@@ -2535,7 +2553,12 @@
}
connector = obj_to_connector(obj);
- drm_crtc_convert_umode(&mode, umode);
+ ret = drm_crtc_convert_umode(&mode, umode);
+ if (ret) {
+ DRM_DEBUG_KMS("Invalid mode\n");
+ goto out;
+ }
+
ret = drm_mode_detachmode(dev, connector, &mode);
out:
mutex_unlock(&dev->mode_config.mutex);